Method and system for generating a diagnostic signal of an engine component using an in-cylinder pressure sensor

Abstract

A method and a control module for diagnosing an engine component function includes a comparison module comparing an in-cylinder pressure signal to a threshold and a fault indication module generating a diagnostic signal for an engine component in response to comparing.

1. A method comprising:
 generating an in-cylinder pressure signal for an engine; 
 comparing the in-cylinder pressure signal to a threshold; and 
 generating a diagnostic signal for a component of the engine in response to the comparing, 
 wherein comparing the in-cylinder pressure signal to the threshold comprises comparing the in-cylinder pressure signal to a profile. 
 
     
     
       2. A method as recited in  claim 1  wherein generating the diagnostic signal for the component of the engine comprises generating the diagnostic signal for a reactivation-deactivation module. 
     
     
       3. A method as recited in  claim 1  wherein generating the diagnostic signal for the component of the engine comprises generating the diagnostic signal for a crankshaft position sensor. 
     
     
       4. A method as recited in  claim 1  wherein generating the diagnostic signal for the component of the engine comprises generating the diagnostic signal for an oil control valve. 
     
     
       5. A method as recited in  claim 1  wherein generating the diagnostic signal for the component of the engine comprises generating the diagnostic signal for a switchable roller finger follower. 
     
     
       6. A method as recited in  claim 5  wherein generating the in-cylinder pressure signal comprises generating at least one of a slope and an integral of a pressure-volume curve and wherein the comparing comprises comparing the at least one of the slope and the integral of the pressure-volume curve. 
     
     
       7. A method as recited in  claim 1  wherein comparing the in-cylinder pressure signal to the threshold comprises comparing a root mean square error between the in-cylinder pressure signal and a reference pressure signal to the threshold. 
     
     
       8. A method as recited in  claim 7  wherein the threshold comprises a reactivation-deactivation threshold. 
     
     
       9. A method as recited in  claim 1  wherein generating the in-cylinder pressure signal comprises generating in-cylinder pressure signals for each cylinder of the engine, wherein the engine includes an internal combustion engine. 
     
     
       10. A method comprising:
 generating an in-cylinder pressure signal for an engine; 
 comparing the in-cylinder pressure signal to a threshold; and 
 generating a diagnostic signal for a component of the engine in response to the comparing, 
 wherein generating the diagnostic signal for the component of the engine comprises generating the diagnostic signal for cylinder valves. 
 
     
     
       11. A method as recited in  claim 10  wherein generating the diagnostic signal for the cylinder valves comprises generating the diagnostic signal for the closing of at least one of an intake valve and an exhaust valve. 
     
     
       12. A method as recited in  claim 10  wherein generating the diagnostic signal for the cylinder valves comprises generating the diagnostic signal for closing of a valve using a coefficient of variation of a cylinder indicated mean effective pressure (IMEP). 
     
     
       13. A control system comprising:
 a comparison module comparing an in-cylinder pressure signal to a threshold, wherein comparing the in-cylinder pressure signal to the threshold comprises comparing the in-cylinder pressure signal to a profile; and 
 a fault indication module generating a diagnostic signal for a component of an engine in response to the comparing. 
 
     
     
       14. A control system as recited in  claim 13  wherein the diagnostic signal comprises a cylinder valve diagnostic signal. 
     
     
       15. A control system as recited in  claim 13  wherein the in-cylinder pressure signal corresponds to an indicated mean effective pressure (IMEP). 
     
     
       16. A control system as recited in  claim 13  wherein the diagnostic signal comprises a reactivation-deactivation module diagnostic signal. 
     
     
       17. A control system as recited in  claim 13  wherein the diagnostic signal comprises a crankshaft position sensor diagnostic signal. 
     
     
       18. A control system as recited in  claim 13  wherein the diagnostic signal comprises an oil control valve diagnostic signal. 
     
     
       19. A control system as recited in  claim 13  wherein the diagnostic signal comprises a switchable roller finger follower diagnostic signal.